Photoresist pattern trimming methods

Abstract

Provided are methods of trimming a photoresist pattern. The methods comprise: (a) providing a semiconductor substrate; (b) forming a photoresist pattern on the substrate, wherein the photoresist pattern is formed from a chemically amplified photoresist composition comprising: a matrix polymer comprising an acid labile group; a photoacid generator; and a solvent; (c) coating a photoresist trimming composition on the substrate over the photoresist pattern, wherein the trimming composition comprises: a matrix polymer, an aromatic acid that is free of fluorine; and a solvent; (d) heating the coated substrate, thereby causing a change in polarity of the photoresist matrix polymer in a surface region of the photoresist pattern; and (e) contacting the photoresist pattern with a rinsing agent to remove the surface region of the photoresist pattern, thereby forming a trimmed photoresist pattern. The methods find particular applicability in the manufacture of semiconductor devices.

What is claimed is: 
     
       1. A method of trimming a photoresist pattern, comprising:
 (a) providing a semiconductor substrate; 
 (b) forming a photoresist pattern on the substrate, wherein the photoresist pattern is formed from a chemically amplified photoresist composition comprising: a matrix polymer comprising an acid labile group; a photoacid generator; and a solvent; 
 (c) providing a photoresist trimming composition comprising a matrix polymer, an aromatic acid that is free of fluorine, and an organic solvent, wherein the aromatic acid is present in the photoresist trimming composition in an amount of from 0.01 to 20 wt % based on total solids of the photoresist trimming composition, and then applying the photoresist trimming composition to the substrate over the photoresist pattern to form a coated subsrate; 
 (d) heating the coated substrate, thereby causing a change in polarity of the matrix polymer of the photoresist pattern in a surface region of the photoresist pattern; and 
 (e) contacting the photoresist pattern with a rinsing agent to remove the surface region of the photoresist pattern, thereby forming a trimmed photoresist pattern. 
 
     
     
       2. The method of  claim 1 , wherein the aromatic acid comprises an acid of the general formula (I): 
       
         
           
           
               
               
           
         
         wherein: R 1  independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C20 aryl group or a combination thereof, optionally containing one or more group chosen from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 1  independently represents a group chosen from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; a and b are independently an integer from 0 to 5; and a +b is 5 or less. 
       
     
     
       3. The method of  claim 1 , wherein the aromatic acid comprises an acid of the general formula (II): 
       
         
           
           
               
               
           
         
         wherein: R 2  and R 3  each independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C16 aryl group or a combination thereof, optionally containing one or more group chosen from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 2  and Z 3  each independently represents a group chosen from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; c and d are independently an integer from 0 to 4; c +d is 4 or less; e and f are independently an integer from 0 to 3; and e +f is 3 or less. 
       
     
     
       4. The method of  claim 1 , wherein the aromatic acid comprises an acid of the general formula (III) or (IV): 
       
         
           
           
               
               
           
         
         wherein: R 4 , R 5  and R 6  each independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C12 aryl group or a combination thereof, optionally containing one or more group chosen from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 4 , Z 5  and Z 6  each independently represents a group chosen from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; g and h are independently an integer from 0 to 4; g +h is 4 or less; i and j are independently an integer from 0 to 2; i +j is 2 or less; k and 1 are independently an integer from 0 to 3; and k +l is 3 or less; 
       
       
         
           
           
               
               
           
         
         wherein: R 4 , R 5  and R 6  each independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C12 aryl group or a combination thereof, optionally containing one or more group chosen from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 4 , Z 5  and Z 6  each independently represents a group chosen from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; g and h are independently an integer from 0 to 4; g +h is 4 or less; i and j are independently an integer from 0 to 1; i +j is 1 or less; k and l are independently an integer from 0 to 4; and k +l is 4 or less. 
       
     
     
       5. The method of  claim 1 , wherein the aromatic acid comprises an acid of the general formula (V): 
       
         
           
           
               
               
           
         
         wherein: R 7  and R 8  each independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C14 aryl group or a combination thereof, optionally containing one or more group chosen from carboxyl, carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 7  and Z 8  each independently represents a group chosen from hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; m and n are independently an integer from 0 to 5; m +n is 5 or less; o and p are independently an integer from 0 to 4; and o +p is 4 or less. 
       
     
     
       6. The method of  claim 1 , wherein the aromatic acid comprises an acid of the general formula (VI): 
       
         
           
           
               
               
           
         
         wherein: X is O or S; R 9  independently represents a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C5-C20 aryl group or a combination thereof, optionally containing one or more group chosen from carbonyl, carbonyloxy, sulfonamido, ether, thioether, a substituted or unsubstituted alkylene group, or a combination thereof; Z 9  independently represents a group chosen from carboxyl, hydroxy, nitro, cyano, C1 to C5 alkoxy, formyl and sulfonic acid; q and r are independently an integer from 0 to 3; and q +r is 3 or less. 
       
     
     
       7. The method of  claim 1 , wherein the rising agent comprises water or an aqueous alkaline solution. 
     
     
       8. The method of  claim 1 , wherein the rinsing agent comprises an organic solvent or solvent mixture. 
     
     
       9. The method of  claim 1 , wherein the aromatic acid is present in the photoresist trimming composition in an amount of from 0.01 to 20 wt % based on total solids of the photoresist trimming composition. 
     
     
       10. The method of  claim 9 , wherein the matrix polymer of the photoresist trimming composition is present in the photoresist trimming composition in an amount of from 80 to 99 wt % based on total solids of the photoresist trimming composition. 
     
     
       11. The method of  claim 1 , wherein the aromatic acid is a sulfonic acid. 
     
     
       12. The method of  claim 11 , wherein the aromatic acid is p-toluenesulfonic acid. 
     
     
       13. The method of  claim 11 , wherein the aromatic acid is 2,4-dinitrobenzenesulfonic acid. 
     
     
       14. The method of  claim 1 , wherein the photoresist trimming composition is applied to the substrate by spin-coating. 
     
     
       15. The method of  claim 1 , wherein a content of the solvent of the photoresist trimming composition is from 90 to 99 wt % based on the trimming composition. 
     
     
       16. The method of  claim 1 , wherein the matrix polymer of the photoresist trimming composition is present in the photoresist trimming composition in an amount of from 80 to 99 wt % based on total solids of the photoresist trimming composition.